Breaking shortcode?

I have a small addon:

function beer_search(){

global $wp_query;

$this_post_id = $wp_query->post->ID;
        if(get_post_meta($this_post_id, 'beer_search', true) == 'true')
        {
//              echo "IS THIS THING ON";

$wptest_maindb = new wpdb(DB_USER, DB_PASSWORD, DB_NAME, DB_HOST);
$beer_search_connection = $wptest_maindb->get_results("SELECT * FROM wp_inventory");

foreach ($beer_search_connection as $container) {
                                echo "Name " . $container->inventory_name;
                                }

//$thestuff = $wpdb->get_results("SELECT * FROM wp_inventory");
//foreach ($thestuff as $container) {
//      echo $container->inventory_name . ', ';
//      echo $container->inventory_description . '<br />';
        }

}

//add_action('loop_start', 'beer_search');
//add_action('the_content', 'beer_search');
add_filter('the_content', 'beer_search');

This addon breaks shortcode for some reason. Any suggestions?